<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<div style="width: 200px;height: 200px;background-color: blue">
    <div>我是一个div元素</div>
</div>
<div style="width: 200px;height: 200px;background-color: red"></div>
</body>
</html>